The persistent phosphor SrAl_(2)O_(4):Eu^(2+),Dy^(3+)is the subject of numerous investigations.One often neglected aspect is that in this phosphor,as well as in Sr_(4)Al_(14)O_(25):Eu^(2+),Dy^(3+),there are two differ...The persistent phosphor SrAl_(2)O_(4):Eu^(2+),Dy^(3+)is the subject of numerous investigations.One often neglected aspect is that in this phosphor,as well as in Sr_(4)Al_(14)O_(25):Eu^(2+),Dy^(3+),there are two different Sr^(2)+sites which can be occupied by the dopant Eu^(2+)ions,We first introduce a general scheme of possible energy transfers in these persistent phosphor materials including explicitly both europium ions,This scheme is used as a generic starting point to study experimentally specific pathways.We illustrate this application with the study of the effect of excitation wavelength(444 and 382 nm)on the afterglow of differently doped SrAl_(2)O_(4):Eu^(2+),Dy^(3+)samples,as well as on the emission decay curves.With the same excitation intensity under 444 nm excitation,the resulting afterglow intensity is stronger than under near UV excitation.At 382 nm,Eu^(2+)ions on both Sr^(2)+s ites in SrAl_(2)O_(4)are excited,but at room temperature the blue emission is quenched,leading to a loss of photons.The observed effects can further be associated with the ratio of Eu^(2+)ions and trap states which are modulated by the concentrations of Eu^(2+)and Dy^(3+)in SrAl_(2)O_(4),as well as by temperature,Increasing the nominal Dy^(3+)content from 0.1 mol%to 0.5 mol%with respect to Sr results in the doubling of the integrated afterglow intensity and confirms thus that Dy^(3+)ions are indeed involved in the trapping process,The concentration of trap states is much lower than the concentration of Eu^(2+)ions,as even with low excitation densities,a plateau of integrated afterglow intensity(corresponding to the total number of accessible traps)is reached.We postulate that an important fraction of excited Eu^(2+)ions can potentially transfer their energy to trap states.Once that all traps are filled or in a dynamical filling-depletion process under illumination(with thermal and/or optical depletion processes),for the remaining Eu^(2+)a"normal"steady-state emission is observed.The luminescence decay curves at 520 nm measured at 77 K show a mono-exponential decay with a common lifetime of about 1140 ns for all 5 samples under 437 nm excitation,while under 375 nm excitation,a feed process originating from the energy transfer between Eu^(2+)ions is demonstrated.Under 375 nm excitation,the non-exponential decay observed at 440 nm can be quantitatively associated to a Forster energy transfer process with R_(0)=1.58(8)nm.For the overall understanding of the afterglow processes,it appears that one has to consider the individual contributions of all active ions on different lattice sites.展开更多
A series of Ba5Si8O（21）：0.02Eu^2＋,0.09RE^3＋ persistent phosphors were synthesized by the solid-state reaction method.The measurement results of photoluminescence（PL）,phosphorescence and thermoluminescence（TL）...A series of Ba5Si8O（21）：0.02Eu^2＋,0.09RE^3＋ persistent phosphors were synthesized by the solid-state reaction method.The measurement results of photoluminescence（PL）,phosphorescence and thermoluminescence（TL）were analysed and discussed.The XRD results showed that samples codoped with different RE^3＋ were Ba5Si8O（21） single pure phase.Under the excitation,all samples exhibited a broad Eu^2＋ characteristic emission,and the La^3＋ co-doped sample emitted the brightest photoluminescence even though its persistent luminescence property was the worst because of the weakest electronegativity.However,Nd^3＋ electronegativity was suitable,thus after activation,the Ba5Si8O（21）：Eu^2＋,Nd^3＋ sample had the best persistent luminescence performance with the highest phosphorescence intensity and the persistent luminescence decay time beyond 8 h.The Nd^3＋ co-doped sample also had the largest thermoluminescence integral area which proved effectively it had longer persistent luminescence time.The luminescence mechanism was also proposed to study the photoluminescence and persistent luminescence process.These results showed that RE^3＋ electronegativities were distinctly important for persistent phosphors and choosing suitable electronegativity codopant was conducive to enhancing the phosphorescent performance.展开更多
Near-infrared(NIR)persistent phosphors have attracted extensive research interest owing to their distinct wavelength features and self-sustained luminescence properties.However,the high-energy ultraviolet light that i...Near-infrared(NIR)persistent phosphors have attracted extensive research interest owing to their distinct wavelength features and self-sustained luminescence properties.However,the high-energy ultraviolet light that is consistently used to charge these phosphors has compromised some promising applications,especially for biomedical imaging.Herein,we have successfully utilized long-wavelength 635 nm redlight to achieve intense NIR persistent luminescence in a MgGeO_(3):Mn^(2+),Yb^(3+)phosphor.Seconds to minutes of 635 nm red-light charging can result in long-lasting NIR afterglow at around 680 nm for longer than 12 h.The photon trapping and detrapping processes in the MgGeO_(3):Mn^(2+),Yb^(3+)phosphor were investigated in detail by varying the 635 nm red laser output power and the excitation duration,which indicate that a two-photon upconversion charging process is responsible for NIR persistent luminescence upon red-light illumination.The red-light-charging capability and self-sustained NIR luminescence properties make this material perfectly suited to applications across a wide number of fields,such as acting as ideal optical probes for deep-tissue bio-imaging and developing optical data storage technology for information security systems.展开更多
Persistent luminescence is an optical phenomenon where solid phosphors can store photoenergy in defects and release the energy by luminescence after stopping excitation.Due to the intriguing optical characteristics,th...Persistent luminescence is an optical phenomenon where solid phosphors can store photoenergy in defects and release the energy by luminescence after stopping excitation.Due to the intriguing optical characteristics,the defect luminescence based persistent phosphors have attracted enormous attention in recent decades,especially in biomedical fields such as biosensing and bioimagin8.Persistent luminescence nanoparticles(PLNPs)can effectively avoid the autofluorescence interference from complex samples or tissues,leading to significantly improved sensitivity in biological analysis.In this review,we summarized the methods to control the optical performance of PLNPs from the perspectives of controlled synthesis and defect regulation,and emphasized the close relationship between their optical performance and applications.We further provided a summary about a series of PLNPs nanoprobes designed by our group for biosensing and bioimaging.Our efforts,summarized in this review,will not only open a window for manipulating luminescence in PLNPs,but also further promote the application of PLNPs in biomedicine.展开更多
We developed bright yellow-emitting long persistent luminescence(LPL)materials Sr_(4)Al_(14)O_(25):Mn^(2+)and Sr_(4)Al_(14)O_(25):Mn^(2+),N(N=Zr^(4+),Ho^(3+),Er^(3+))by high temperature solid-state reaction.The additi...We developed bright yellow-emitting long persistent luminescence(LPL)materials Sr_(4)Al_(14)O_(25):Mn^(2+)and Sr_(4)Al_(14)O_(25):Mn^(2+),N(N=Zr^(4+),Ho^(3+),Er^(3+))by high temperature solid-state reaction.The addition of Zr^(4+),Ho^(3+)and Er^(3+)can regulate trap distributions and improve energy storage ability of the materials.The LPL perfo rmance of SAO:Mn^(2+),Ho^(3+)is optimal,considering LPL intensity and duration time.Bright LPL of SAO:Mn^(2+),Ho^(3+)can be observed for 3 h by naked eyes in dark after removing the excitation source.Profiles of LPL spectra are different from those of PL,because the two types of Mn^(2+)centers do not play equal parts in LPL and photoluminescence(PL).Trap depths of TL peaks centered at 354 K(peak 1)and 455 K(peak 2)are 0.60 and 0.72 eV,respectively.And peak 1 at 354 K is the effective TL peak responsible for LPL.In SAO:Mn^(2+),Ho^(3+),Mn^(2+)ions doped in Al^(3+)sites serve as emitting centers,and positively charged HoSr defects are the main effective trap centers.Finally,a feasible LPL mechanism of SAO:Mn^(2+),Ho^(3+)was proposed to clarify the generation process of LPL.展开更多
Persistent phosphors emitting in the ultraviolet(UV)spectral region have attracted great attention in recent years,owing to their promising potential in many advanced applications ranging from photocatalysis to photot...Persistent phosphors emitting in the ultraviolet(UV)spectral region have attracted great attention in recent years,owing to their promising potential in many advanced applications ranging from photocatalysis to phototherapy.Here,we report the development of a novel UVA emissive persistent phosphor by doping Bi^(3+)into a LiScGeO_(4) host.The LiScGeO_(4):Bi^(3+)persistent phosphor can be effectively charged using a standard 254 nm UV lamp and emits intense,long-lasting persistent luminescence peaking at 365 nm for longer than 120 h.Besides,the UVA persistent luminescence from the pre-irradiated LiScGeO_(4):Bi^(3+)phosphor can be repeatedly rejuvenated by short-time photostimulation with low-energy white,red and near-infrared(NIR)light.The long-lasting UVA afterglow,together with the photostimulated persistent luminescence(PSPL)capability,makes the LiScGeO_(4):Bi^(3+)phosphor an important element of persistent luminescence materials in the UVA spectral region.This UVA persistent phosphor is expected to find exciting applications in the fields of medical therapy and environmental research.展开更多
Here,multimodal fluorescent materials of Ca_(3)Al_(2)Ge_(3)O_(12):Mn^(2+),Cr^(3+)were synthesized by the traditional high-temperature solid-state reaction method.In this garnet Ca_(3)Al_(2)Ge_(3)O_(12) structure,Mn^(2...Here,multimodal fluorescent materials of Ca_(3)Al_(2)Ge_(3)O_(12):Mn^(2+),Cr^(3+)were synthesized by the traditional high-temperature solid-state reaction method.In this garnet Ca_(3)Al_(2)Ge_(3)O_(12) structure,Mn^(2+)and Cr^(3+)ions occupy dodecahedral sites(Ca sites)and hexahedral sites(Al sites),and can produce dynamic colortunable persistent luminescence at different concentrations,different excitations,and different temperatures;in particular,continuous luminescence with temperature(300 K–473 K)shows a color change from green to deep red.Through detailed pyrolysis studies and theoretical calculations,it is demonstrated that the double-trap structure existing in the host makes the persistent luminescence color temperaturedependent.Anti-counterfeiting and industrial inspection molds were successfully accomplished,which means Ca_(3)Al_(2)Ge_(3)O_(12):Mn^(2+),Cr^(3+)may be used in anti-counterfeiting and industrial inspection.展开更多
Persistent luminescent phosphors(PLPs)have attracted much attention in anti-counterfeiting,biosensing and bioimaging due to their characteristic properties of emitting long persistent luminescence(PersL)after excitati...Persistent luminescent phosphors(PLPs)have attracted much attention in anti-counterfeiting,biosensing and bioimaging due to their characteristic properties of emitting long persistent luminescence(PersL)after excitation ceases.However,most of the PLPs developed so far have only one PersL emission peak,which limits their application in advanced anti-counterfeiting and precise biosensing.Here,a series of dual-emissive Zn_(2)GeO_(4):x%Tb^(3+)/y%Bi^(3+)PLPs was prepared by codoping Tb^(3+)ions and Bi^(3+)ions to significantly improve the trap depth and trap density,resulting in a 16.8-fold increase in PersL intensity compared to the Zn_(2)GeO_(4) host.The photoluminescence(PL)color was adjusted to pale blue under 254 nm UV excitation by trap depth engineering,while the PersL color was green,and the PL color under 365 nm UV excitation was yellow.In addition,the PersL intensity was dramatically increased by 16.8 times by codoping Tb^(3+)and Bi^(3+).Therefore,multi-mode anti-counterfeiting was achieved by multi-stimulus response.Furthermore,the dual-emission band was designed as a ratiometric PersL aptasensor for the detection of mucin 1.The detection linearity ranged from 0.1 to 100 ng mL^(−1) with a detection limit of 0.036 to 1 ng mL^(−1).This novel PLP with a dual-emission band expands the application range of PLPs.展开更多
The advent of alternating current light-emitting diodes(AC-LEDs)based on persistent luminescence(PersL)phosphors is a major breakthrough in terms of long service lifetime,reduced production cost,and high energy utiliz...The advent of alternating current light-emitting diodes(AC-LEDs)based on persistent luminescence(PersL)phosphors is a major breakthrough in terms of long service lifetime,reduced production cost,and high energy utilization efficiency.However,the efficiency of the current PersL based AC-LEDs for flicker reduction in each AC cycle needs to be improved.To address this issue,herein,we develop a series of green-emitting persistent luminescence(PersL)phosphors BaY_(2)Al_(2)Ga_(2)SiO_(12):Ce^(3+),Bi^(3+)(BYAGSO:Ce^(3+),Bi^(3+))via a defect engineering approach,whose PersL can be efficiently activated by blue-light.A strategy that introduces bismuth with multivalent states into BYAGSO:0.04Ce^(3+)is proposed to optimize the PersL intensity.Theτ80 value(the time when the PersL intensity reaches 80%of its initial value)of BYAGSO:0.04Ce^(3+),0.01Bi^(3+)is about 30 ms,which demonstrates its effectiveness in minimizing flicker from AC-LEDs.Meanwhile,with the aid of excitation temperature-dependent and fading thermoluminescence(TL)experiments,the trapping levels related to Bi^(3+)in BYAGSO:Ce^(3+),Bi^(3+)are also investigated through the initial rise method.Furthermore,we fabricate an AC-LED device using the phosphor BYAGSO:0.04Ce^(3+),0.01Bi^(3+)and the commercial red PersL phosphor Sr_(0.75)Ca_(0.25)S:Eu^(2+)(SCS:Eu^(2+))with an InGaN blue-emitting chip,which shows warm-white emission with a reduced percent flicker of 47.06%.These results demonstrate that the BYAGSO:Ce^(3+),Bi^(3+)phosphor might be a promising candidate for lowflicker AC-LEDs.展开更多
Far ultraviolet-C(far-UVC;200-230 nm)luminescent materials have garnered significant interest in recent years,driven by the growing demands for applications such as disinfection and solar-blind imaging due to their di...Far ultraviolet-C(far-UVC;200-230 nm)luminescent materials have garnered significant interest in recent years,driven by the growing demands for applications such as disinfection and solar-blind imaging due to their distinct wavelength features.However,the research and development of far-UVC persistent phosphors are lacking.Here,we report the realization of far-UVC persistent luminescence in CaSO_(4):Pr^(3+)and CaSO_(4):Pb^(2+)phosphors,which show emissions peaking at 220 nm and 230 nm with a long persistence time of>24 h after ceasing X-ray excitation.This is by far the shortest UVC afterglow emission to the best of our knowledge.The far-UVC afterglow from the charged phosphors can be readily detected using a solar-blind UV camera in both indoor-lighting and outdoor environments owing to the absence of background noise from ambient light.The continuous photostimulation of indoor white LED light and outdoor sunlight has different impacts on the far-UVC afterglow performance of CaSO_(4):Pr^(3+)and CaSO_(4):Pb^(2+)phosphors,which is elucidated by the decay time-dependent thermoluminescence(TL)curves under different light conditions.This study expands the field of persistent luminescence to the far-UVC spectral region and will inspire the discovery of more excellent far-UVC persistent phosphors.展开更多
ZnGa_(2)O_(4):Cr^(3+)persistent luminescent phosphors(PLPs)have been widely applied in bioimaging and photonics due to their ultra-long near-infrared(NIR)afterglow.However,UV and visible excitation currently in use ha...ZnGa_(2)O_(4):Cr^(3+)persistent luminescent phosphors(PLPs)have been widely applied in bioimaging and photonics due to their ultra-long near-infrared(NIR)afterglow.However,UV and visible excitation currently in use have shallow penetration depths or harmful effects on organisms,which limit long-term bioimaging.Therefore,developing NIR PLPs excited by NIR light is urgent for bioimaging.Here,Zn_(1-x)(Li/Ga)_(x)Ga_(2)O_(4):Cr^(3+)(x=0-1)NIR PLPs were synthesized.All the newly introduced Ga^(3+)ions occupy the tetrahedral sites.However,with increasing Li^(+)/Ga^(3+)content,Li^(+)ions first occupy the tetrahedral position,then partially enter octahedral sites,and completely occupy the octahedral sites at x=1.The incorporation of Li^(+)/Ga^(3+)contributes to weakened crystal field strength,which leads to a deeper trap depth and a wider trap energy level.Complete replacement of Zn^(2+)with Li^(+)/Ga^(3+)ions leads to the splitting of the trap energy level into two-divided ones,which reduces the electron transfer between deep/shallow traps and makes the deep trap energy level come close to the 2E energy level of Cr^(3+).Therefore,an enhanced NIR afterglow excited by the low-energy NIR light is found for the Li^(+)/Ga^(3+)doped sample.This work provides a new category for NIR-absorptive-NIR-emissive PLPs and proposes a new phosphor for long-term bioimaging.展开更多
基金Project supported by the Swiss National Science Foundation(200020_182494,200021_169033)Innosuisse(25902.1 PFNM-NM,15217.1PFIW-IW)。
文摘The persistent phosphor SrAl_(2)O_(4):Eu^(2+),Dy^(3+)is the subject of numerous investigations.One often neglected aspect is that in this phosphor,as well as in Sr_(4)Al_(14)O_(25):Eu^(2+),Dy^(3+),there are two different Sr^(2)+sites which can be occupied by the dopant Eu^(2+)ions,We first introduce a general scheme of possible energy transfers in these persistent phosphor materials including explicitly both europium ions,This scheme is used as a generic starting point to study experimentally specific pathways.We illustrate this application with the study of the effect of excitation wavelength(444 and 382 nm)on the afterglow of differently doped SrAl_(2)O_(4):Eu^(2+),Dy^(3+)samples,as well as on the emission decay curves.With the same excitation intensity under 444 nm excitation,the resulting afterglow intensity is stronger than under near UV excitation.At 382 nm,Eu^(2+)ions on both Sr^(2)+s ites in SrAl_(2)O_(4)are excited,but at room temperature the blue emission is quenched,leading to a loss of photons.The observed effects can further be associated with the ratio of Eu^(2+)ions and trap states which are modulated by the concentrations of Eu^(2+)and Dy^(3+)in SrAl_(2)O_(4),as well as by temperature,Increasing the nominal Dy^(3+)content from 0.1 mol%to 0.5 mol%with respect to Sr results in the doubling of the integrated afterglow intensity and confirms thus that Dy^(3+)ions are indeed involved in the trapping process,The concentration of trap states is much lower than the concentration of Eu^(2+)ions,as even with low excitation densities,a plateau of integrated afterglow intensity(corresponding to the total number of accessible traps)is reached.We postulate that an important fraction of excited Eu^(2+)ions can potentially transfer their energy to trap states.Once that all traps are filled or in a dynamical filling-depletion process under illumination(with thermal and/or optical depletion processes),for the remaining Eu^(2+)a"normal"steady-state emission is observed.The luminescence decay curves at 520 nm measured at 77 K show a mono-exponential decay with a common lifetime of about 1140 ns for all 5 samples under 437 nm excitation,while under 375 nm excitation,a feed process originating from the energy transfer between Eu^(2+)ions is demonstrated.Under 375 nm excitation,the non-exponential decay observed at 440 nm can be quantitatively associated to a Forster energy transfer process with R_(0)=1.58(8)nm.For the overall understanding of the afterglow processes,it appears that one has to consider the individual contributions of all active ions on different lattice sites.
基金Project supported by the National Natural Science Foundation of China(61265004,51272097)the Foundation of Application Research of Yunnan Province,China(2011FB022)
文摘A series of Ba5Si8O（21）：0.02Eu^2＋,0.09RE^3＋ persistent phosphors were synthesized by the solid-state reaction method.The measurement results of photoluminescence（PL）,phosphorescence and thermoluminescence（TL）were analysed and discussed.The XRD results showed that samples codoped with different RE^3＋ were Ba5Si8O（21） single pure phase.Under the excitation,all samples exhibited a broad Eu^2＋ characteristic emission,and the La^3＋ co-doped sample emitted the brightest photoluminescence even though its persistent luminescence property was the worst because of the weakest electronegativity.However,Nd^3＋ electronegativity was suitable,thus after activation,the Ba5Si8O（21）：Eu^2＋,Nd^3＋ sample had the best persistent luminescence performance with the highest phosphorescence intensity and the persistent luminescence decay time beyond 8 h.The Nd^3＋ co-doped sample also had the largest thermoluminescence integral area which proved effectively it had longer persistent luminescence time.The luminescence mechanism was also proposed to study the photoluminescence and persistent luminescence process.These results showed that RE^3＋ electronegativities were distinctly important for persistent phosphors and choosing suitable electronegativity codopant was conducive to enhancing the phosphorescent performance.
基金supported by the financial support from the National Natural Science Foundation of China(grant no.51902184)Natural Science Foundation of Shandong Province(grant no.ZR2019BEM028)the“Qi-Lu Young Scholar Fund”(grant no.31370088963167)from Shandong University.
文摘Near-infrared(NIR)persistent phosphors have attracted extensive research interest owing to their distinct wavelength features and self-sustained luminescence properties.However,the high-energy ultraviolet light that is consistently used to charge these phosphors has compromised some promising applications,especially for biomedical imaging.Herein,we have successfully utilized long-wavelength 635 nm redlight to achieve intense NIR persistent luminescence in a MgGeO_(3):Mn^(2+),Yb^(3+)phosphor.Seconds to minutes of 635 nm red-light charging can result in long-lasting NIR afterglow at around 680 nm for longer than 12 h.The photon trapping and detrapping processes in the MgGeO_(3):Mn^(2+),Yb^(3+)phosphor were investigated in detail by varying the 635 nm red laser output power and the excitation duration,which indicate that a two-photon upconversion charging process is responsible for NIR persistent luminescence upon red-light illumination.The red-light-charging capability and self-sustained NIR luminescence properties make this material perfectly suited to applications across a wide number of fields,such as acting as ideal optical probes for deep-tissue bio-imaging and developing optical data storage technology for information security systems.
基金This work was supported by the National Natural Science Foundation of China(No.21925401)the Natural Science Foundation of Hunan Province,China(No.2020JJ4173).
文摘Persistent luminescence is an optical phenomenon where solid phosphors can store photoenergy in defects and release the energy by luminescence after stopping excitation.Due to the intriguing optical characteristics,the defect luminescence based persistent phosphors have attracted enormous attention in recent decades,especially in biomedical fields such as biosensing and bioimagin8.Persistent luminescence nanoparticles(PLNPs)can effectively avoid the autofluorescence interference from complex samples or tissues,leading to significantly improved sensitivity in biological analysis.In this review,we summarized the methods to control the optical performance of PLNPs from the perspectives of controlled synthesis and defect regulation,and emphasized the close relationship between their optical performance and applications.We further provided a summary about a series of PLNPs nanoprobes designed by our group for biosensing and bioimaging.Our efforts,summarized in this review,will not only open a window for manipulating luminescence in PLNPs,but also further promote the application of PLNPs in biomedicine.
基金Project supported by the National Natural Science Foundation of China(51802137)the Natural Science Foundation of Shandong Province of China(ZR2019BEM010)+1 种基金the State Key Research Projects of Shandong Natural Science Foundation(ZR2020KB019)Yantai High End Talent Introduction"Double Hundred Plan"Special Fund,the Research Fund of Ludong University(ZR2021004)。
文摘We developed bright yellow-emitting long persistent luminescence(LPL)materials Sr_(4)Al_(14)O_(25):Mn^(2+)and Sr_(4)Al_(14)O_(25):Mn^(2+),N(N=Zr^(4+),Ho^(3+),Er^(3+))by high temperature solid-state reaction.The addition of Zr^(4+),Ho^(3+)and Er^(3+)can regulate trap distributions and improve energy storage ability of the materials.The LPL perfo rmance of SAO:Mn^(2+),Ho^(3+)is optimal,considering LPL intensity and duration time.Bright LPL of SAO:Mn^(2+),Ho^(3+)can be observed for 3 h by naked eyes in dark after removing the excitation source.Profiles of LPL spectra are different from those of PL,because the two types of Mn^(2+)centers do not play equal parts in LPL and photoluminescence(PL).Trap depths of TL peaks centered at 354 K(peak 1)and 455 K(peak 2)are 0.60 and 0.72 eV,respectively.And peak 1 at 354 K is the effective TL peak responsible for LPL.In SAO:Mn^(2+),Ho^(3+),Mn^(2+)ions doped in Al^(3+)sites serve as emitting centers,and positively charged HoSr defects are the main effective trap centers.Finally,a feasible LPL mechanism of SAO:Mn^(2+),Ho^(3+)was proposed to clarify the generation process of LPL.
基金financial support from the National Natural Science Foundation of China(grant no.51902184)Shandong Provincial Natural Science Foundation(grant no.ZR2019BEM028)+3 种基金the“Qi-Lu Young Scholar Fund”(grant no.31370088963167)from Shandong Universitythe financial support from the Natural Science Foundation of Jiangsu Province(BK20180230)China Postdoctoral Science Foundation(2018M632673)Fundamental Research Funds of Shandong University(2019JCG004).
文摘Persistent phosphors emitting in the ultraviolet(UV)spectral region have attracted great attention in recent years,owing to their promising potential in many advanced applications ranging from photocatalysis to phototherapy.Here,we report the development of a novel UVA emissive persistent phosphor by doping Bi^(3+)into a LiScGeO_(4) host.The LiScGeO_(4):Bi^(3+)persistent phosphor can be effectively charged using a standard 254 nm UV lamp and emits intense,long-lasting persistent luminescence peaking at 365 nm for longer than 120 h.Besides,the UVA persistent luminescence from the pre-irradiated LiScGeO_(4):Bi^(3+)phosphor can be repeatedly rejuvenated by short-time photostimulation with low-energy white,red and near-infrared(NIR)light.The long-lasting UVA afterglow,together with the photostimulated persistent luminescence(PSPL)capability,makes the LiScGeO_(4):Bi^(3+)phosphor an important element of persistent luminescence materials in the UVA spectral region.This UVA persistent phosphor is expected to find exciting applications in the fields of medical therapy and environmental research.
基金supported by the National Natural Science Foundation of China(No.51902080)the central government to guide local scientific and Technological Development(No.206Z1102G and 216Z1101G)Post-graduate’s Innovation Fund Project of Hebei University(HBU2022bs014).
文摘Here,multimodal fluorescent materials of Ca_(3)Al_(2)Ge_(3)O_(12):Mn^(2+),Cr^(3+)were synthesized by the traditional high-temperature solid-state reaction method.In this garnet Ca_(3)Al_(2)Ge_(3)O_(12) structure,Mn^(2+)and Cr^(3+)ions occupy dodecahedral sites(Ca sites)and hexahedral sites(Al sites),and can produce dynamic colortunable persistent luminescence at different concentrations,different excitations,and different temperatures;in particular,continuous luminescence with temperature(300 K–473 K)shows a color change from green to deep red.Through detailed pyrolysis studies and theoretical calculations,it is demonstrated that the double-trap structure existing in the host makes the persistent luminescence color temperaturedependent.Anti-counterfeiting and industrial inspection molds were successfully accomplished,which means Ca_(3)Al_(2)Ge_(3)O_(12):Mn^(2+),Cr^(3+)may be used in anti-counterfeiting and industrial inspection.
基金supported by the National Natural Science Foundation of China(62105333)the Natural Science Foundation of Xiamen,China(3502Z20227253)+1 种基金the Key Research Program of the Chinese Academy of Sciences(ZDRW-CN-2021-3)the Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2020ZZ114 Z).
文摘Persistent luminescent phosphors(PLPs)have attracted much attention in anti-counterfeiting,biosensing and bioimaging due to their characteristic properties of emitting long persistent luminescence(PersL)after excitation ceases.However,most of the PLPs developed so far have only one PersL emission peak,which limits their application in advanced anti-counterfeiting and precise biosensing.Here,a series of dual-emissive Zn_(2)GeO_(4):x%Tb^(3+)/y%Bi^(3+)PLPs was prepared by codoping Tb^(3+)ions and Bi^(3+)ions to significantly improve the trap depth and trap density,resulting in a 16.8-fold increase in PersL intensity compared to the Zn_(2)GeO_(4) host.The photoluminescence(PL)color was adjusted to pale blue under 254 nm UV excitation by trap depth engineering,while the PersL color was green,and the PL color under 365 nm UV excitation was yellow.In addition,the PersL intensity was dramatically increased by 16.8 times by codoping Tb^(3+)and Bi^(3+).Therefore,multi-mode anti-counterfeiting was achieved by multi-stimulus response.Furthermore,the dual-emission band was designed as a ratiometric PersL aptasensor for the detection of mucin 1.The detection linearity ranged from 0.1 to 100 ng mL^(−1) with a detection limit of 0.036 to 1 ng mL^(−1).This novel PLP with a dual-emission band expands the application range of PLPs.
基金financially supported by the National Key R&D Program of China(Grant No.2019YFA0709101)the Key Research Program of the Chinese Academy of Sciences(Grant No.ZDRW-CN-2021-3-3-06)the National Natural Science Foundation of China(Grant No.52072364,51902305,22175169)。
文摘The advent of alternating current light-emitting diodes(AC-LEDs)based on persistent luminescence(PersL)phosphors is a major breakthrough in terms of long service lifetime,reduced production cost,and high energy utilization efficiency.However,the efficiency of the current PersL based AC-LEDs for flicker reduction in each AC cycle needs to be improved.To address this issue,herein,we develop a series of green-emitting persistent luminescence(PersL)phosphors BaY_(2)Al_(2)Ga_(2)SiO_(12):Ce^(3+),Bi^(3+)(BYAGSO:Ce^(3+),Bi^(3+))via a defect engineering approach,whose PersL can be efficiently activated by blue-light.A strategy that introduces bismuth with multivalent states into BYAGSO:0.04Ce^(3+)is proposed to optimize the PersL intensity.Theτ80 value(the time when the PersL intensity reaches 80%of its initial value)of BYAGSO:0.04Ce^(3+),0.01Bi^(3+)is about 30 ms,which demonstrates its effectiveness in minimizing flicker from AC-LEDs.Meanwhile,with the aid of excitation temperature-dependent and fading thermoluminescence(TL)experiments,the trapping levels related to Bi^(3+)in BYAGSO:Ce^(3+),Bi^(3+)are also investigated through the initial rise method.Furthermore,we fabricate an AC-LED device using the phosphor BYAGSO:0.04Ce^(3+),0.01Bi^(3+)and the commercial red PersL phosphor Sr_(0.75)Ca_(0.25)S:Eu^(2+)(SCS:Eu^(2+))with an InGaN blue-emitting chip,which shows warm-white emission with a reduced percent flicker of 47.06%.These results demonstrate that the BYAGSO:Ce^(3+),Bi^(3+)phosphor might be a promising candidate for lowflicker AC-LEDs.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.12474407 and 51902184)Key Research and Development Program of Shandong Province(Major Scientific and Technological Innovation Project)(Grant No.2021CXGC011101)+1 种基金the State Key Laboratory of Infrared Physics,Shanghai Institute of Technical Physics,Chinese Academy of Sciences(Grant No.SITP-NLIST-YB-2022-10)the“Qi-Lu Young Scholar Fund”of Shandong University.
文摘Far ultraviolet-C(far-UVC;200-230 nm)luminescent materials have garnered significant interest in recent years,driven by the growing demands for applications such as disinfection and solar-blind imaging due to their distinct wavelength features.However,the research and development of far-UVC persistent phosphors are lacking.Here,we report the realization of far-UVC persistent luminescence in CaSO_(4):Pr^(3+)and CaSO_(4):Pb^(2+)phosphors,which show emissions peaking at 220 nm and 230 nm with a long persistence time of>24 h after ceasing X-ray excitation.This is by far the shortest UVC afterglow emission to the best of our knowledge.The far-UVC afterglow from the charged phosphors can be readily detected using a solar-blind UV camera in both indoor-lighting and outdoor environments owing to the absence of background noise from ambient light.The continuous photostimulation of indoor white LED light and outdoor sunlight has different impacts on the far-UVC afterglow performance of CaSO_(4):Pr^(3+)and CaSO_(4):Pb^(2+)phosphors,which is elucidated by the decay time-dependent thermoluminescence(TL)curves under different light conditions.This study expands the field of persistent luminescence to the far-UVC spectral region and will inspire the discovery of more excellent far-UVC persistent phosphors.
基金supported in part by the Natural Science Foundation of Liaoning Province(Grant 2020-MS-081)the National Natural Science Foundation of China(Grants 51302032,U21A2045,and 52172112).
文摘ZnGa_(2)O_(4):Cr^(3+)persistent luminescent phosphors(PLPs)have been widely applied in bioimaging and photonics due to their ultra-long near-infrared(NIR)afterglow.However,UV and visible excitation currently in use have shallow penetration depths or harmful effects on organisms,which limit long-term bioimaging.Therefore,developing NIR PLPs excited by NIR light is urgent for bioimaging.Here,Zn_(1-x)(Li/Ga)_(x)Ga_(2)O_(4):Cr^(3+)(x=0-1)NIR PLPs were synthesized.All the newly introduced Ga^(3+)ions occupy the tetrahedral sites.However,with increasing Li^(+)/Ga^(3+)content,Li^(+)ions first occupy the tetrahedral position,then partially enter octahedral sites,and completely occupy the octahedral sites at x=1.The incorporation of Li^(+)/Ga^(3+)contributes to weakened crystal field strength,which leads to a deeper trap depth and a wider trap energy level.Complete replacement of Zn^(2+)with Li^(+)/Ga^(3+)ions leads to the splitting of the trap energy level into two-divided ones,which reduces the electron transfer between deep/shallow traps and makes the deep trap energy level come close to the 2E energy level of Cr^(3+).Therefore,an enhanced NIR afterglow excited by the low-energy NIR light is found for the Li^(+)/Ga^(3+)doped sample.This work provides a new category for NIR-absorptive-NIR-emissive PLPs and proposes a new phosphor for long-term bioimaging.
